This invention pertains to a taphole assembly and a method of installing it. The invention has particular use in steelmaking furnaces such as basic oxygen furnaces.
Tapholes are well-known; they are designed to conduct molten metal from inside a furnace where it has been melted or refined to another container, for example a ladle. They are also used in open-hearth furnaces, electric arc furnaces, and blast furnaces in the steel industry, as well as for pouring molten nonferrous metals. For example, U.S. Pat. No. 3,329,420 and U.S. Pat. No. 3,416,779 show tapholes in place in basic oxygen furnaces. In addition, U.S. Pat. No. 3,295,845, U.S. Pat. No. 3,554,523 and British Pat. No. 1,485,878 show the structure of such tapholes in greater detail.
Most of the tapholes shown in the above patents have joints in the molten metal passage itself; these joints offer points of attack on the refractory used to construct the taphole. The monolithic taphole shown in U.S. Pat. No. 3,416,779 is apparently set in a rammed or cast in situ section of the lining. The use of rammed or cast in situ material again offers a point of attack for the slag and molten metal on the refractory lining, rammed or cast in situ refractory generally being less resistant to attack by such materials than the same composition in brick form.
The taphole of the present invention is designed to overcome the foregoing problems, providing a monolithic metal carrying channel without joints in a structure which does not require that rammed or cast in situ material be exposed to molten slag and metal.